Self-optimization of plasmonic nanoantennas in strong femtosecond fields

• DOI: 10.1364/optica.4.001038
• Publication Date: 2017-08-28T21:33:13Z
• Authors: Liping Shi; Bianca Iwan; Rana Nicolas; Quentin Ripault; Jose R. C. Andrade; Seunghwoi Han; Hyunwoong Kim; Willem Boutu; Dominik Franz; Torsten Heidenblut; Carsten Reinhardt; Bert Bastiaens; Tamas Nagy; Ihar Babushkin; Uwe Morgner; Seung-Woo Kim; Günter Steinmeyer; Hamed Merdji; Milutin Kovacev
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy; [PHYS] Physics [physics]

Plasmonic dimer nanoantennas can significantly boost the electric field strength in gap region, allowing for a modification of feed geometry by femtosecond laser illumination.Using resonant bowtie antennas to enhance low-fluence oscillator, here we experimentally demonstrate highly localized reshaping antennas, resulting self-optimization antenna shape.From high-resolution scanning electron micrographs and two-dimensional energy dispersive x-ray maps, analyze near-field enhanced subwavelength ablation at nanotips deposition ablated materials gap.The dominant mechanism is attributed nonthermal transient unbonding atoms electrostatic acceleration ions.This process driven surface plasmon emission, with subsequent vacuum.This impeded presence an ambient gas.A maximum sixfold enhancement third-harmonic yield observed during process.